US431216A

US431216A - Regulation of dynamo-electric machines

Info

Publication number: US431216A
Authority: US
Publication date: 1890-07-01
Anticipated expiration: 1907-07-01

Description

7 REGULATION OF DYNAMO ELECTRIC MACHINES.

No. 431,216. Patented July 1,1890.

mne ceds: Int/c9120? L R v/Z441, W X f f/m. w vy wm Oz Qgw UNITED STATES PATENT OFFICE.

WVILLIAM STANLEY, JR, OF GREAT BARRINGTON, MASSACHUSETTS.

REG U LATION 0F DYNAMO-ELECTRIC MACHIN ES.

SPECIFICATION forming part of Letters Patent No. 431,216, dated July 1, 1890.

Application filed July 29, 1889. Serial No. 319,019. (No model.)

To all whom it may concern:

Be it known that I, VVILLIAM' STANLEY, Jr., a citizen of the United States, residing in Great Barringtomin the county of Berkshire and State of Massachusetts, have invented a new and Improved Method of Regulation for Dynamo-Electric Machines, (Case No. 131,) of which the following is a specification.

The object of the invention is to automatically vary the potential of the current supplied to the field-magnet coils of a dynamoelectric machine in sympathy with variations in the current required to operate translating devices in a work-circuit supplied with current by the machine, so as to maintain a constant, rising, or required difference of potential between the terminals of the workcircuit. Such variation I primarily accomplish by increasing or decreasing, as the case may be, the number of effective lines of magnetic force threading certain of the armaturecoils.

In carrying the invention into effect the armature of a dynamo-electric machine is wound with two coils or sets of coils, one of which supplies current to a work-circuit, while the current developed in the other coil or set of coils is redirected and used to excite the field-magnets of the machine. The armature is so constructed as to afford a path for the passage of a portion of the lines of force of the field outside of the armature-coils which supply currents to the field-magnet coil, so that these coils are normally affected by only a portion of the field of force. The relative position of the two sets of coils upon the armature-core are such that when .a given exciting-coil is in a position of zero electro-motive force a corresponding coil of the other set, which supplies current to the work-circuit, is at or near the position in which maximum potential is induced in it. One or more turns of Wire connected in series with the latter coil "are wound adjacent to and parallel with the given exciting-coil. The terminals of the exciting-coil are connected to a commutator in order to supply current constant in direction for the proper excitation of the field-magnets, while the terminals of those coils which supply current to the work-circuit are connected to collector-rings or to commutator-plates in the usual manner.

The invention will be best understood by reference to the accompanying drawing, which is a diagram illustrating a cross-section of a dynamo constructed to operate in accordance with the invention.

Referring to the figure, N S represent the field-lilagnets of a dynamo having field-magnet coils m m.

C is the armature-core, upon which are wound separate coils A and B. The coils A and B are wound at approximately right angles to one another, so that while one is in its position of zero elect-ro-motive force the other is at or near that position of maximum induced electro-motive force. The armature-coil B is wound in a recess 1), formed in the core 0, into which the wires are introduced through an opening 0. After the wires are introduced into the recess 1) the opening 0 is closed by a plug or strip of iron a, secured in the opening. Thus a closed magnetic circuit is formed, giving passage to a portion of the lines of the field of force outside of the coil B. Parallel with the coil B and contained in the recess 1) with it is wound a coil consisting of a few turns of wire a, connected in series with the coil A. The coil A is connected with the mains L L of the work-circuit WV by means of collector-rings c 0, while the terminals of the coil B are conn'ected with the field-magnet coils m m by means of a commutator D and brushes (1 (1 It is evident that as current flows in the coil a a field of force will be set up around the wire, which will tend to change the direction of the adjacent lines of magnetic force in the field of the machine, and an increase of current in the coil a will cause a greater or less number oflines of force to thread the coil B when in its position of zero electromotive force, according to the direction in which current is flowing in the wire a.

l Vhen translating devices are connected in parallel in the work-circuit, an increase in the number of translating devices in circuit causes a decrease in the diiferenoe of potential between the terminals of the coil A supplying current to the work-circuit, and in order to keep the difference of potential constant an increased excitation of the fieldmagnets is necessary. The fall in potential is, however, accompanied by an increased flow of current and more current flows through the coil a. The coil a is so connected that the magnetic field due to the fiow of current through it tends to drive inward the lines of force passing through the armature-core exterior to the coil B; hence upon an increase of current in the coil a a greater number of lines of force will thread the coil B, thus i11- creasing the potential developed in it as it rotates, and consequently increasing the excitation of the field-magnets and the difference of potential between the terminals of the coil A. Conversely, upon a decrease in the fiow of current in the coil a more of the lines of force of the field will pass through the armature-core exterior to the coil B, and the potential upon the coil will diminish with acorresponding diminution in the excitation of the field-magnets. If it is desired to produce the opposite effectsthat is, to cause a decrease in the field strength upon an increase in the iiow of current in the work-circuit-as, for example, when it is desired to maintain a constant current upon the work-circuitthe connections of the wire a should be reversed, so that the lines of the magnetic field set up by the current fiowing through it will act in a direction to drive the lines of the field of force of the machine outward, thus decreasing the number of lines of force included in the coil 13 upon an increase in the flow of current in the wire a, and consequently decreasing the excitation of the field-magnets.

' It is evident that with each reversal of current in the coil a the position of the coil itself will be reversed, and thus the lines of force developed by the current flowing in the coil a will maintain a constant direction as related to the direction of the lines of force of the magnetic field of the machine.

For convenience of illustration I have shown the machine as constructed with only two armature-coils, the one supplying current to the work-circuit and the other to the fieldmagnet coils. I11 practice, however, it is desirable, for reasons well understood by those skilled in the art, that there should be two or more armature-coils in each set, the regulating-coils being arranged with reference to the field-supplying and work-supplying coils in the manner already shown.

\Vhile my invention is applicable to those dynamos which supply other than alternating currents for the operation of translating devices in the work-circuit, its especial advantage lies in the fact that by means of it a constant difference of potential or constant current value may be automatically maintained between the terminals of an alternate-current dynamo through great variations in the amount of load upon the workcircuit.

I have not attempted to describe herein all possible means of carrying my invention into effect, but only the best form of apparatus for the purpose now known to me, various modifications of which will readily occur to those skilled in the art; nor doI claim herein the particular form of apparatus herein described, as I have made it the subject of another application for Letters Patent.

'What I do claim as new, and desire to secure by Letters Patent, is

1. The hereinbefore-dcscribed method of generating and regulating electric currents, which consists in generating currents in a set of armature-coils and maintaining a field of force thereby, causing a portion of the lines of force constituting such field to pass on tside of such coils and controlling the number of the lines of force passing outside of such coils by means of currentdeveloped in ,a second set of armaturecoils lying within such field.

2. The hereinbefore-described method of generating and regulating electric currents, which consists in generating currents in a set of armature-coils and maintaining afield of force thereby, causing a portion of the lines of force constituting such field to traverse the armature at points where they willhave little or no inductive effect upon such coils, and controlling the number of such ineffective lines of force by means of alternating currents flowingin a second set of coils upon the armature.

3. The l1016l1lllGfOlO-(lOSCllIJCCI method of generating and regulating electric currents, which consists in generatingcurrents in a set of armature-coils and maintaining a field of force thereby, causing a portion of the lines of force of the field to traverse the armature at points where they will have little or no inductive effect upon such coils, and by means of alternating currents flowing in. a second set of coils upon such armature diverting a portion of such ineffective lines of force into positions of inductive effect upon said firstmentioned coils.

In testimony whereofI have hereunto subscribed my name this 18th day of June, A.D. 1889.

XVILLIAH STANLEY, JR.

Witnesses.

SANDS F. RANDALL, D. IvEs MACKIE.

IIO